HMS M.33 lurks in the bottom of the old Number 1 Dry Dock looking very small compared to her neighbour in the Number 2 Dry Dock, HMS Victory.
However, size-wise, she fits in nicely between the launches and other small vessels in Boathouse 4 and the bigger warships.
Launched in May 1915, she is one of just three British warships from World War I still in existence, and is the sole remaining British veteran of both the Dardanelles Campaign of 1915-1916, and the Russian Civil War which followed.
Known as a Monitor, she is basically just a rapidly-built metal box, with two powerful second-hand guns. Her shallow draft allowed her to get close inshore and support troop landings by firing at targets on land.
Lacking any comforts, she was crammed with up to 72 officers and men, and could be away from home for three years or more.
After descending to the bottom of the dock and stepping on board, visitors treated to a "stunning immersive battle experience". Ah well, it's a chance to sit down anyway.